A tilt position adjusting mechanism is a mechanism for adjusting an angle of inclination of a steering wheel to a position which is the easiest to drive by adapting to a figure and preference of a driver. When the angle of inclination of the steering wheel is adjusted, a tilting clamp mechanism is brought into an unclamped state once, the angle of inclination of the steering wheel is adjusted continuously under the state, and thereafter, the tilting clamp mechanism is brought into a clamped state again.
According to the steering device having the tilt position adjusting mechanism, a vehicle attaching bracket is fixed to a vehicle body, and a fastening rod is inserted to a tilt adjusting long groove of the vehicle body attaching bracket and a column. When tilting is clamped, the fastening rod is fastened by pressing a fixed cam in an axial direction by a movable cam which is pivoted by operating an operating lever, and the column is pressed to the vehicle body attaching bracket to clamp. However, when a fastening force of the fastening rod is weak, in second collision in which a driver is crashed to the steering wheel, the column is moved in a tilting direction, and there is a concern that an air bag provided the steering cannot receive a passenger at an effective position.
As a mechanism for preventing the column from being moved in the second collision, there is a tilt clamp mechanism in which a fixed tilt lock gear is installed at a side plate of the vehicle body attaching bracket, and a movable tilt lock gear which is brought in mesh with the fixed tilt lock gear is inserted to the fastening rod.
According to the configuration, when tilting is clamped, by bringing the movable tilt lock gear in mesh with the fixed tilt lock gear by fastening the fastening rod, a holding force in the tilting direction is increased, and even when an impact load by the second collision is operated to the steering wheel, the column is prevented from being moved in the tilting direction.
According to the steering device which increases the holding force in the tilting direction in this way, when the tilting is clamped, if the fastening rod is fastened, the side plate attached with the fixed tilt lock gear is elastically deformed. Therefore, positions of the movable tilt lock gear and the fixed tilt lock gear in a vehicle width direction relative to each other are changed, and there is a concern that meshing of the movable tilt lock gear and the fixed lock gear is failed.
According to a steering device of Japanese Unexamined Patent Application Publication No. 2008-137393 which is installed with a tilting clamp mechanism, a movable tilt lock gear is outwardly fitted to a movable cam with a clearance therebetween, and an elastic member in a ring-like shape is inserted between the movable cam and the movable tilt lock gear, and a washer made of a resin is interposed between the movable tilt lock gear and an operating lever to fasten to a fastening rod. Thereby, the movable tilt lock gear is made to be able to move in a tilting direction and in a vehicle width direction relative to the movable cam, and a degree of freedom is provided to a position at which the movable tilt lock gear and the fixed tilt lock gear are brought in mesh with each other.
However, according to the steering device of Japanese Unexamined Patent Application Publication No. 2008-137393 which is installed with the tilting clamp mechanism, titling is clamped by way of the elastic member in the ring-like shape, and therefore, it is difficult to increase a rigidity when tilting is clamped. Further, the elastic member in the ring-like shape is compressed when tilting is clamped, and therefore, it is not easy to select an elastic material which has a sufficient durability from elastic materials of rubber and the like as the material of the elastic member in the ring-like shape.
According to a steering device of Japanese Examined Utility Model Application Publication No. 59-41892 which is installed with a tilt clamp mechanism, one side plate of a vehicle body attaching bracket is reinforced by a rib, the other side plate a rigidity of which is reduced is elastically deformed in a vehicle width direction, tilting is clamped by pressing a column to the vehicle body attaching bracket, and a rigidity of the vehicle body attaching bracket is increased when tilting is clamped. However, the steering device of Japanese Examined Utility Model Application Publication No. 59-41892 which is installed with the tilt clamp mechanism is not applied to a tilt clamp mechanism in which a holding force in a tilting direction is increased by bringing a movable tilt lock gear in mesh with a fixed lock gear.    Japanese Unexamined Patent Application Publication No. 2008-137393    Japanese Examined Utility Model Application Publication No. 59-41892